[amsat-bb] BBQ Dishes for S-band

[Jon Ogden <na9d-2@xxxxxxxxxxxxx>]

Hey gang,

Since I was off the air on the birds for nearly a year I didn't keep up much
on the reflector.  Now I am back and am reading some things I'm not quite
sure of.

The biggest I see is that people say that the BBQ dish antennas are not
sufficient or are at best marginal for SSB communications on AO-40.  But my
experience in the last couple days says something different.  I know that
K5GNA was (is?) selling two sizes of BBQ dishes.  I have the larger size.

Last night I worked about 6 stations in an hour with my setup including a VK
on CW.  He was the first and the squint was nearly 30 degrees at my
location.  The rest were all from the US, but I was getting some of the guys
at levels of S4 to S5 peaks.  Lots of fades due to the squint, but when I
turned the radio off the squint was still above 20 degrees.

Having worked a lot of AO-10 before my antennas went down last year, I am
used to weak signals on the birds, fades, etc.  I don't find AO-40 to be
that bad.  Sure, it would be nice to be stronger, but it's certainly
adequate.

In my short experience what I think I see much more of are people afraid to
use enough downlink power, IMHO.  I know I am new to the bird, but last
Saturday, I heard many, many guys who were at S0 to S1.  Yet the beacon was
at S8.  Even assuming 2 dB per S-unit as one person suggested, that would
put most of the people I heard somewhere between 14 and 16 dB below the
beacon.  Now dBs are dBs and are relative.  So yes, getting a larger dish
will improve reception over all, but still I see no reason to run 16 dB or
more below the beacon when everything I have looked at talks about levels 10
to 12 dB below it.  I don't see any reason why one should not easily be able
to operate at S2 to S3 with no problem.  That makes copy much easier.

Finally, I think a necessity for easier copy is to get a ClearSpeech DSP
processor to eliminate some of the white noise.  Is anyone else using one of
those?  I heard one at Dayton last year and was impressed.

73,

Jon
NA9D

-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)

Citizen of the People's Democratic Republik of Illinois

Life Member: ARRL, NRA
Member:  AMSAT, DXCC

http://www.qsl.net/na9d   <- Updated on 1/12/03!!!

"A life lived in fear is a life half lived."


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